This isn't really related to LM2... They just released SM3DL, and there were very mixed opinions on Super Mario Sunshine. I'd buy a second one, but it's unlikely it'll happen. It's more of a gimmick/experiment Mario game.
The game did end with a sort of cliffhanger, The Running Man a.k.a. (Il Piantissimo) finding the magic paintbrush haha. I'd probably buy it. It was one of my most favorite games of all time. There were many frustrating moments (watermelon, cataquacks,yoshi boat-hoping to island) but it was very fun overall. Maybe without voice acting though, Bowser's voice was horrible. Like 'Beef' said, I'd also be happy with just a 3D remake. I can't play my gamecube game anymore because my little brother scratched it up.